Memory is one type of integrated circuitry, and is used in electronic systems for storing data. Integrated memory is usually fabricated in one or more arrays of individual memory cells. The memory cells are configured to retain or store memory in at least two different selectable states. In a binary system, the states are considered as either a “0” or a “1”. In other systems, at least some individual memory cells may be configured to store more than two levels or states of information.
One type of memory is phase change memory (PCM). Such memory utilizes phase change material as a programmable material. Example phase change materials that may be utilized in PCM are chalcogenide materials.
The phase change material reversibly transforms from one phase to another through application of appropriate stimulus. Each phase may be utilized as a memory state, and thus an individual PCM cell may have two selectable memory states that correspond to two inducible phases of the phase change material.
The phase change materials may be detrimentally affected (i.e., “poisoned”) if they are exposed oxygen, and accordingly it is desired to develop new architectures and fabrication methods which alleviate or prevent such oxygen exposure.